Statistical analyses
The data distribution was tested for normality using the Shapiro-Wilk
test and log-transformed when necessary for all the measured variables.
One-way analysis of variance (ANOVA) was used to test the effects of
mycorrhizal type (AM vs ECM) on nutrient absorption potential, nutrient
resorption, and mass loss as well as all traits of green leaves and
absorptive roots. Significant differences between means were compared
using Tukey’s honest significant difference test. Correlations among
processes and traits were determined by calculating Pearson’s
correlation coefficients for three categories: all species and species
hosting AM and ECM fungi. In order to obtain a proxy for the resource
economics of green leaves, principal component analyses (PCA) were
performed on a suite of leaf economics traits, including SLA, LTD,
concentrations of C, N, P, and lignin in green leaves (Table S2). Based
on the first axis of the PCA, we obtained the PC1 scores of each species
using the ‘psych’ package in R. The standard major axis regression was
then performed to evaluate the relationships between the PC1 score and
nutrient-associated processes (i.e. nutrient absorption potential,
nutrient resorption, and decomposition) for the three categories above
using the ‘SMATR’ package in R. Results were considered statistically
significant at P < 0.05. All statistical analyses were
performed using R v.3.4.4 and SAS version 9.4 (SAS Institute Inc., Cary,
USA).